There are few things in this world that I can say I am an expert in (in fact I can only name two(: ) but hog hunting in Texas is one of those things. (shooting ducks is the other). First of all I personally wouldn't recommend a 45-70. Its not that its a bad caliber (personally i love the 45-70, its a very powerful round) but the thing is it isn't the cheapest round to shoot and for the size hog you mentioned (100 pounders) you don't need that much power. Believe me, I have shot hogs with alot of different calibers. When it comes to hunting hog, the gun you use should be based off of what your planning on doing. if your planning on shooting one massive hog then 7mm bolt action is hard to beat, but it sounds to me like your trying to get rid of multiple hogs. For such a task there isn't a "Best" gun to use, its just what works best for you. I for one would use a 30-30 lever action. why you might ask? because, the 30-30 can be bought for an affordable price (i paid 14 dollars for my last box of 20 which I got just a month or two ago), the 30-30 is also I fairly accurate caliber, I usually don't use 30-30 for more than 250 yard but it can be done. Not to mention that the 30-30 is a light kicking caliber, so you should have no problem taking multiple shots before the herd can get away. Me and my brother have taken 10 hogs in one shooting before ( we both had lever actions. I had a 30-30 which held 6 rounds and he had a .44 which held 10), with that being said I think 30-30 is a wonderful round, but if you don't have one of those I would go with the .44 magnum.... yeah it can be heavy but those extra rounds could pay off. you mentioned you carried a .357 on your hip. the .357 is a great caliber, unfortunately hogs can be hard to put down, in case of one charging you (not likely to happen but its happened before) i would carry Hornady critical defense if I were you. good luck with the hunting, and post pictures if you get any hogs!